Epilepsy is a common childhood condition affecting approximately 326,000 youth in the United States. Adolescents with epilepsy are at significant risk for poor social and academic outcomes, neurobehavioral comorbidities (i.e., internalizing and externalizing symptoms), and poor treatment adherence. Studies have shown that one potential reason for these poor outcomes are deficits in executive functioning (EF), defined as the skills necessary for goal-directed and complex activities, including problem-solving, initiation, monitoring, organization, planning, self-regulation and working memory. EF deficits have been documented in 1/3 of youth with epilepsy, which is 3 times the prevalence in healthy youth. Evidence-based interventions to improve EF could play a critical role in preventing adverse outcomes (e.g., psychological comorbidities, non-adherence to the treatment regimen) and promoting optimal functioning in adolescents with epilepsy; however none exists for this vulnerable population. The aim of the current study is to develop an individually-tailored intervention to improve EF in adolescents with epilepsy (Executive Functioning Intervention-Epilepsy; EFI-E) through an iterative, patient-centered process that includes: 1) identification of the unique needs of adolescents with epilepsy and their families based on focus group feedback (Phase 1), 2) usability testing of a revised intervention protocol to elicit feedback on the applicability, content, and individualized approach (Phase 2), and finally 3) an open-label trial t establish the feasibility, accessibility, acceptability, and preliminary effect of the EFI-E for adolescents with epilepsy (Phase 3). We plan to recruit 50 participants for all 3 phases (Phase 1; n=6-10; Phase 2; n=6-10; Phase 3; n=30). Participants will have at least one clinically-elevated EF subscale or at least two at-risk subscale scores on (> 1 standard deviation above the mean) on the Behavior Rating Inventory of Executive Function (BRIEF)) to qualify for the EFI-E. EFI-E will consist of 8-10 web-based modules addressing foundational EF skills including: problem-solving skills, self-regulation, working memory, monitoring, and planning/organizing. The first three modules of the intervention will be fixed; however, the remaining modules will be tailored based on the adolescent's most prominent EF deficit and preference. Each online module will be accompanied by a videoconference with a therapist to review the skills and problem solve around an adolescent-identified goal. Baseline and post-treatment questionnaires will be completed by adolescents and primary caregivers and electronically-monitored adherence will be obtained throughout the open trial. This project addresses the critical need for evidence-based interventions to improve EF, reduce neurobehavioral comorbidities, and improve AED non-adherence in a high risk epilepsy population. This intervention has the potential to ultimately improve academic performance, social functioning, sleep, stigma, and health-related quality of life in a large subgroup of adolescents with epilepsy. This study also lays the foundation for larger multi-site clinical trial examining the efficacy of EFI-E in improving adolescent outcomes.